Biomedical subjects

G Seitz

Publications and source records attributed to G Seitz.

167 records · Page 10Linked to original sources

PubMedDate not supplied

Overexpression of nm23-H4 RNA in colorectal and renal tumours.

A new member of the nm23 gene family, designated nm23-H4, was cloned recently. Nm23-H4 is a mitochondrial protein. To determine whether nm23-H4 could have a function in tumour progression like nm23-H1 or nm23-H2, we analysed nm23-H4 expression in 18 renal tumours and 42 colorectal carcinomas obtained from patients who underwent curative resection. As compared to the corresponding healthy tissue, 14 renal tumours and 41 colorectal carcinomas showed increased nm23-H4 mRNA expression. While the increase was only moderate in renal cell carcinoma, a strong overexpression of nm23-H4 was noted in most colorectal carcinomas, possibly indicating a role of this gene in tumour genesis. The nm23-H4 transcript levels did not correlate with tumour stage, grade of differentiation or lymph node involvement.

Adenocarcinoma, Clear Cell↗

PubMedDate not supplied

Potentially therapeutically relevant differences of antisense oligonucleotide uptake in CD34+ hematopoietic stem cells, leukemic blasts and cancer cells from patients.

Antisense oligonucleotide (ON) technology, e.g. against drug resistance or antiapoptotic factors, may play an important role in future cancer chemotherapy. An unanswered question in this field is the capacity for uptake of antisense molecules in normal and malignant patients' cells. Therefore, we examined the cellular uptake of FITC-labeled phosphorothioate modified ONs in: i) cells from the T-lymphoblastoid cell line CCRF-CEM, ii) CD34+ hematopoietic progenitors from healthy donors, iii) blasts from ALL or AML patients, iv) cells from the ovarian cancer cell line A2780 and v) cancer cells from malignant fluids. The cationic polymer ExGen was taken as a carrier for transfection, while FITC-ON uptake was evaluated by flow cytometry. We found marked differences between these cell types. Cancer cells from the cell line A2780 and from patients showed a distinctly enhanced uptake compared to hematopoietic progenitors and leukemic blasts. Since bone marrow toxicity substantially limits any conventional chemotherapeutic regimen, a better ON uptake in cancer cells compared to hematopoietic precursors might give an advantage for therapeutic approaches using e.g. ON-based chemosensitization.

Antigens, CD34↗

PubMedDate not supplied

Tumor-specific methylation patterns of erbB2 (HER2/neu) sequences in gastro-intestinal cancer.

To determine whether the sporadically occurring amplification of the oncogene erbB2/HER2 in gastrointestinal carcinomas is associated with additional changes of this sequence, DNA from 17 colorectal and 5 stomach carcinomas was analyzed for copy number, sequence rearrangement and DNA methylation by Southern blot hybridization. Amplification was detected in two cases. By applying the isochizomers Hpall and Mspl we tested for alterations in the DNA methylation status. Whereas in colon tumors with non-amplified erbB2 this status was unchanged, one case with erbB2 amplification showed additional MspI bands indicating a methylation of the amplified gene sequences. In stomach carcinoma, however, we detected differences between tumor and mucosa samples but not between amplified and non-amplified tumor samples. Independent of the DNA methylation status, significant amounts of the erbB2 oncoprotein were detected in the cases with gene amplification; weaker immunostaining of erbB2 was also seen in a few additional tumors.

Blotting, Southern↗

PubMedDate not supplied

Influence of steroid hormones on pS2/BCEI gene expression in xenografted colon tumors.

The biological function of the hormone inducible human pS2/BCEI gene, cloned from the breast cancer cell line MCF-7, still remains unknown. Our aim was to determine the in vivo influence of steroid hormones on pS2 expression and tumour growth in colorectal tumours. We transplanted aliquots of human colon tumours into male and female nude mice and studied tumour growth and expression of the pS2/BCEI gene by immunostaining and mRNA analysis. Our results show that the sex of the host and therefore the hormonal background does not play a dominant role in pS2 expression and growth of the xenografts.

Animals↗

PubMedDate not supplied

NM23-H1 and NM23-H2 gene expression in human renal tumors.

The two nm23 genes, nm23-H1 and nm23-H2, are implicated in the metastatic process and tumor progression in some human tumors. Until now no data exist about nm23 expression in the different types of human renal tumors. To investigate if the nm23 genes play a central role in the progression of renal tumors, we have examined nm23-H1 and nm23-H2 gene expression using Northern-blot analysis and immunohistochemistry. We analysed clear cell type RCC, chromophilic RCC, chromophobic RCC, collecting duct type RCC and renal oncocytomas. Our results indicate that the nm23 genes do not play a central role in the prognosis of renal cell carcinoma in the analysed tumors.

Carcinoma, Renal Cell↗